Lifeblood
by rachelariella
Summary: Brynn Parker is Peter's twin who is just as devoted to defending their neighborhood. Making sure Peter doesn't get himself killed is her main concern, but when new alien weapons hit the streets of Queens, the younger Parker twin realizes that she may need to take a bigger role in their superhero lifestyle to protect her brother


**Disclaimer:** I do not own any Marvel material. Any similarities in storyline or dialogue originated with the movies/comics.  
 **Summary:** Brynn Parker is Peter's twin who is just as devoted to defending their neighborhood. Making sure Peter doesn't get himself killed is her main concern, but when new alien weapons hit the streets of Queens, the younger Parker twin realizes that she may need to take a bigger role in their superhero lifestyle to protect her brother.  
 **A/N:** welcome to my first mcu fic. Please leave a review, favorite, or follow if you enjoyed and let me know what you thought. Thank you!

 **Chapter 1**

Brynn knew the moment Peter walked into the room. His presence caused a sigh of relief to seep between her lips as she turned away from the window to face him. The constant uneasy feeling in the pit of her stomach hadn't relented since her brother left the hotel earlier that day. Even though she was in contact with him and could see everything that happened during the fight, she couldn't calm her nerves until her twin was standing in front of her.

"You look like crap," Brynn murmured as she took in her brother's appearance. He was no longer wearing his new suit and without the mask she could see just how many hits he had taken.

"Feel like crap," Peter said. His sister quirked an eyebrow, daring him to try to continue the lie. He sighed as a knowing smirk tugged at the corner of his lips. "Actually, I feel pretty good."

Brynn returned his smile. "I know."

She closed the distance between them with two short steps. He winced when she touched the edge of the discoloration circling his eye, but quickly tried to cover it up with a nonchalant shrug. "It barely hurts."

"Right," Brynn said, not bothering to prove him wrong. She shook her head as Peter met her gaze. "I told you to stay far away from Captain America and what do you do? Try to take him one-on-one."

"I almost had him."

Brynn pressed her lips into a thin line as she desperately tried not to smile. She forced a nod and cleared her throat. "Mhm."

"What? You don't think I could have won?" Peter narrowed his eyes.

"Maybe if he didn't drop a boarding bridge on you." She smiled when her brother conceded with a faint nod. She rolled onto her tiptoes and wrapped her arms around his neck, resting her chin on his shoulder. "I'm just glad you're okay."

"O ye, of little faith," Peter joked as he put his arms around Brynn, hugging her tighter. It was always such a strange feeling being away from her, even if it was only for a few hours. He never thought of her as anything less than an extension of himself. She was his better half and he didn't even want to think about what it would be like if he didn't have her to rely on through all of this.

"I have faith." She released him and took a step back. "I just have more faith in the Avengers since they're experienced, vetted superheroes."

"Well, technically I am too now."

Skepticism crept into Brynn's expression. "I'm not sure that's how it works."

"I fought with them, helped them win." Peter ran a hand through his hair as he sat back on his bed. "How else would I get in?"

"I don't know, but, in my completely unbiased opinion, making you an official avenger would be the smartest decision they'd ever make." Brynn took the seat beside him on the bed.

"Making _us_ official avengers," her brother corrected. He turned to meet her gaze. "Where I go, you go, remember? I couldn't imagine doing all of it without you."

"I was with you before we were even born, Peter," Brynn paused as she rested her head on his shoulder. "You're never going to have to do this alone."

* * *

 _TWO MONTHS LATER…_

She was ready to hurl herself over the edge of a cliff just for a change in routine. It felt like years since Brynn had gone to Berlin and while she hadn't expected an immediate or dramatic change, she had expected something to be different when she returned home. Instead, it seemed as if her life had only gotten more mundane. Peter was lucky enough to be able to go out and swing from buildings every night in an attempt to be some kind of neighborhood hero, but due to her lack of crime-fighting abilities, Brynn was forced to assist her brother from their bedroom. She could admit that it was fun at first, listening to police scanners and hacking into street cams, but that quickly lost it's excitement factor. Unfortunately, no matter how boring her evenings had become, she made a promise to her brother that she had no intention on breaking.

"He's not going to respond," Brynn murmured, keeping her eyes on her own phone. Against her advice, her brother had just sent his daily check-in text to Happy Hogan, Tony Stark's head of security. "In fact, I'm pretty sure he's ignoring us out of spite _because_ you text him so much."

Peter huffed a sigh when she looked up at him. He shoved his cellphone into his pocket and grabbed onto the subway pole between them. "What else am I supposed to do? Just sit around and wait for him to call? It's been two months, Brynn!"

"I know how long it's been, Peter." She slid a patronizing glance in his direction.

"You said it yourself, we should be out there, doing more important things than helping old ladies cross the street."

"That's not our decision to make," she replied with a forced smile. Lately, she had become the more optimistic one out of the two of them since Peter was steadily losing faith that they'd ever get the call they'd been hoping for. "But I'm sure it'll happen soon enough."

"Why isn't it our decision?" He raised an eyebrow at his twin. Brynn's eyes narrowed on instinct, recognizing her brother's scheming face.

She lowered her voice slightly and angled her head towards Peter. "Because we're two teenagers, conducting our operation out of a bedroom the size of a walk-in closet in Queens, New York."

"It's a little bigger than a walk-in closet," Peter argued, his nose scrunching.

Brynn shook her head. "So not the point I was trying to make."

Her brother rolled his head back on his shoulders, sighing loudly. "I know. I'm just bored out of my mind."

"You're not the only one, but we should have faith that Mr. Stark has a reason for not asking us to do more." She put a hand on his arm and gave him a small squeeze to assure him. "Maybe he just doesn't think we're ready yet."

"But we—"

Brynn continued before he could finish his sentence. "So, we'll have to do everything in our power to show him how wrong he is."

* * *

Ned stared at the younger Parker twin. "How can you say that Captain America is better than Iron Man?"

"Because he's _Captain America_. He's got the powers, he's got the heart, and he's got the looks. He's like the triple threat of superheroes."

Her best friend still looked just as confused. "But… it's Iron Man."

Brynn rolled her eyes. "My point is that if they fought each other, Captain would win, hands down."

"Oh, god, is she back on this 'Captain America can beat anyone' bullshit again?"

Peter nodded as the fourth member of their quartet joined them at the lunch table. Dylan set his plastic tray down beside Brynn's and took the open seat next to her. She didn't bother looking at him, opting to take another bite of her muffin instead.

"When did she ever stop?" Peter asked. Brynn shot him a look from across the table, but he expertly avoided her gaze.

She sighed when she felt Dylan's eyes on her again. "We all know you're in love with Steve Rogers. You can stop talking him up."

Brynn scoffed as she turned to look at her friend. Somehow, she stopped herself from squirming under the scrutiny of his icy blue eyes. "As if he needs me to talk him up. His record speaks for itself."

"Oh yeah? Like the part where he got stuck in an iceberg for sixty years?" Dylan leaned towards her and smirked lightheartedly. Brynn inhaled to gain control of her quickening heart rate.

"He sacrificed—"

Peter groaned, cutting off his sister's train of thought. He ran his hands over his face. "Guys, we've had this exact conversation like a hundred times before. Can we please change the subject?"

"Fine," Brynn said, deciding to take mercy on her twin. She spun around on the bench and stood up. "I'm going to get another chocolate muffin and when I get back we can discuss star wars… or star trek… or something having to do with science."

"Thank you, Bri," Peter called after her and she gave a careless wave over her shoulder as she walked towards the other side of the cafeteria. He waited until his sister was out of earshot to turn his attention to Dylan. "Why do you always get so frustrated when she talks about Captain America? It's just a stupid crush."

"Well, I shouldn't have had to hear about that stupid crush every single day for five years." Dylan paused to pop a French fry in his mouth. "I mean, I get it. Steve Rogers is righteous and handsome and everything she wants in a guy. She doesn't have to keep reminding me about it."

"Sounds like someone's jealous," Ned mumbled under his breath. A foot slammed into his shin underneath the table, causing him to flinch noticeably. Dylan's expression was fixed into a glare when Ned looked up at him. The older boy gave a faint shake of his head before Peter could notice their exchange.

"What—"

"Nothing," Ned and Dylan chorused.

Peter's eyes narrowed, watching them for a few moments. "You guys are acting weird."

Dylan scoffed. "Says the guy who spends half of his day staring at a girl who barely notices he exists."

"She notices he exists, she just doesn't care," Ned said before their friend could try to defend himself.

"Are you guys talking about Liz again?" Brynn asked as she came up behind them. She sat down beside Dylan and smiled knowingly at her brother. It was a feat for him to go a few hours without bringing up the girl he'd been crushing on since freshman year.

"When doesn't he talk about her?" The fifth voice that interjected caused the younger Parker twin to glance to the other end of the lunch table. Sitting there was one of their classmates, MJ, who Brynn talked to on a regular basis, despite her tendency to rarely talk back.

Brynn pointed at her, smiling as she glanced at her brother. "She's got a point."

"No, she doesn't." He threw her a look, but she ignored it easily.

She turned to MJ again. "Do you want to sit with us?"

There was no change in the other girl's expression as she stared back at Brynn. "I already am."

She struggled for a moment to piece together a response. "Right. I meant, do you want to sit closer?"

"Why? I can hear everything you guys say from here," MJ replied, leaving Brynn at a loss for words again. She forced an understanding smile as she nodded at the other girl.

Dylan was already looking at her when she faced him again. "What?"

"You've got such a way with people."

She shot him a mocking glare. "Speaking of location, where were you this morning? Peter and I waited for you, but you never showed. Plus, you missed first period." Brynn raised an eyebrow when Dylan hesitated to answer.

"My mom needed help with something." He shrugged to convince Brynn and his other friends that the reason behind his absence wasn't that important. "Besides, first period is math, which I'm acing."

"Next time, just text us," Peter said before his sister could frame a response. Brynn was known for being the nice twin, but Dylan had a tendency to bring out a rare lightheartedness in her.

"So, you're coming to decathlon practice today?" Ned asked, smoothly changing the subject. Brynn tore her gaze from Dylan and nodded at her other best friend. "I thought you were too busy to join the team."

She shrugged and thrusted her chin in her brother's direction. "Someone has to take Peter's place."

Ned followed Brynn's gaze to her twin. "You're quitting the team?"

Peter pursed his lips as he sighed, looking between his best friend and sister. Brynn mouthed an apology when she remembered his plan. "Well, I was going to tell everyone at practice today that I just don't have the time to do it anymore because of the—"

"Stark internship," Dylan and Ned completed the sentence for him. Peter angled his head at his sister when she failed to muffle a laugh.

Dylan nudged Brynn on the arm. "What I don't get is how Brynn seems to have more free time even though you both got the same internship."

"We have the same workload, I just get mine done faster," she said, smirking widely. "And what I don't finish, I can work on from home. Peter needs a certain kind of setting in order to get stuff done."

Brynn smiled at her brother once he looked up at her and he obviously had the urge to contradict what she said, but logic won out. As much as he wanted to trust his friends with the truth, he knew it was better if they simply believed the story he had constructed with Brynn.

"The point is I'm not leaving you guys high and dry. I can't do it anymore, but Brynn's the next best option." He paused long enough to see her arch an eyebrow at him. " _The_ best option."

Dylan set his eyes on Peter. "Don't you think Brynn's already got enough on her plate? She can't take your place every time you decide to quit something."

"It's fine, really. I can handle it," Brynn interjected quickly. She gave a nonchalant shrug when her friends looked at her. "I got it all under control."

* * *

"Have you noticed that Dylan's been asking a lot of questions lately?"

Brynn shrugged and leaned forward, placing her elbows on her desk as she watched the red dot that represented her brother pause on her laptop screen. "Not really."

"I feel like he's getting suspicious," Peter continued, his voice coming through her earpiece.

She scoffed. "That's probably because you've been acting suspicious, Peter."

"What are you—"

"You're rarely home anymore, you're quitting every extracurricular activity you used to love, and you barely make time to hang out with us," Brynn explained quickly. She stopped herself from continuing, knowing that those three facts would be enough to make her brother see the issue at hand.

"But—"

"I know you're a superhero now, Peter. I'm not saying to give that up. You just… you have to find a way to balance your regular life and all this spidey stuff or people are bound to notice how distracted you are. That's when people start asking questions."

She could hear her brother sigh over the intercom. "So, how do I do that, find a balance?"

"I don't know, but I think it's something you have to figure out on your own or you run the risk of resenting whatever is decided for you."

"Since when did you become the smart twin?"

Brynn scoffed. "I've always been the smart twin."

A comfortable silence fell over them as she leaned back in her chair, shutting her eyes. It was a few minutes before Peter's voice echoed in her ear. "Well, I'm about ready to call it."

"I say that's a smart choice, seeing as how the highlight of your day was slamming someone's face into their own car."

"It was an accident! How I was I supposed to know—"

"Peter, I'm kidding," Brynn said quickly to stop her brother's mini-rant. "Just get back home before May finishes dinner."

"May's cooking?"

"Trying to. Turns out turkey meatloaf is a little more complicated than she thought, but she's giving it her—"

Her brother cut her off. "Hold on a second! Brynn, I think someone's going to rob the bank on 21st street."

"Are you sure?" She sat up and rushed to connect to the server that would give her a view of the live feed on 21st street. It had been months since she had learned how to hack into the street cams on her operating system and it had come in handy with Peter's afternoon antics.

"I'm watching them walk into the bank right now," he responded between heavy breaths. "I got to go."

Brynn bit her lip as she clicked through the different camera feeds until she found the one that gave her the perfect view of the bank. "Should I call the cops?"

"Why? I got this handled, Brynn."

She shook her head and lowered her voice. "Famous last words."

"Thanks for the vote of confidence. Just be on standby. I'll let you know if I need an assist."

"Seems like I'm always on standby," she whispered under her breath to make sure her brother couldn't hear her.

Brynn took the next couple minutes to try to find a backdoor into the security system of the bank, but unlike the street cams, they had an extra firewall that would take too long to crack. She turned her focus to the camera outside the bank and zoomed in to get a better look at the escalating situation inside. It was plain to see that the weapons the robbers were using weren't standard issue, especially when one was used to throw her brother against the wall.

"Peter!" Brynn shouted, momentarily forgetting where she was.

"Brynn?" Her aunt called from the next room. "Is everything all right?"

"Yeah!" She shouted back as she stood from her chair and hurried towards the door. Brynn cracked it open and popped her head out so she could see May in the kitchen. Her aunt's expression was a mix of concern and confusion, but her niece quickly gave her an assuring smile. "Everything's fine. Peter just hung up on me, is all."

May shifted her weight as she put a hand on her hip. "Right. Well, if you talk to him again can you ask him when we should expect him to be home?"

"Of course."

"And I think it would help if we had some kind of schedule so I can keep track of you two a little better," May continued before she could shut the bedroom door.

"Sounds great. I'll tell Peter about it when he gets home. Just let me know when dinner's ready," Brynn said, smiling wide, and closed the door to the bedroom.

She ran back to her desk only to find that neither Peter nor the bank robbers were anywhere in sight. None of the cameras on the street showed them either, but she paused on the one that showed the deli that her twin often visited after school. Most of the shop was destroyed, by some kind of explosion most likely. With the fire still burning, Brynn knew it happened only a few moments ago. She put a finger to her earpiece and tried to make contact with Peter, but there was no response. After a few more tries, she grabbed her phone off the desk and called her brother quicker than she ever had before.

"Goddamn it, Peter!" Brynn exclaimed quietly when the call went straight to voicemail.

"Jeez, what did he do this time?" She tuned on the heels of her feet to come face to face with Ned. He stared back at her with a half-finished Lego Death Star in his hands. "Must have been bad to make you curse."

"Uh…" Brynn inhaled slowly as she tried to piece together a response. "It was nothing serious. He, uh, hung up on me… again. I just got a little angry."

Ned stepped further into her bedroom. "I've only seen you angry like twice in my life."

She put her phone down and folded her arms over her chest. "Not true. I get angry plenty of times, just not around you."

"Right," Ned said, looking unconvinced. He held up the Lego toy set a little higher. "Where can I set up?"

"Uh, Peter's bed, I guess." Brynn gestured to the bottom bunk bed. She watched as he sat down and placed the Death Star on the open spot beside him. "So, did you tell Peter that you were coming over or…?"

"I told him, but I guess he forgot." Ned peered up at her and she couldn't miss the flash of disappointment that crossed his expression.

Brynn shifted her weight and forced a soft smile. "If it makes you feel any better, he's been too busy to spend time with anyone—even me."

"Yeah, but you're his sister—his twin sister. No matter what, you'll always be there for each other," he explained.

"Hey," Brynn murmured as she stepped closer to him. "I will always be here for you. You're my best friend, Ned. That's never going to change."

He held her gaze. "How do you know that?"

She hesitated to answer. "I guess I don't, for sure, but what I do know is that you're a part of my family and family is the most important thing in my life. I wouldn't give up a part of it without a hell of a fight."

"You always know what to say," Ned told her as his eyes dropped to the Death Star.

"It's a gift." Brynn gave a nonchalant shrug of her shoulders. She pointed to the box of Legos that he had brought with him. "Do you want to work on the Death Star together until Peter gets home?"

Her best friend nodded. "Yeah. Don't tell Peter, but you're better at putting on the small pieces, anyways."

"It'll be our secret," Brynn said with a genuine smile. She stepped back until she felt her waist hit her desk and slyly grabbed her phone off it. "I'm going to get some water before we start. Do you want anything to drink, Ned?"

Once he shook his head no, she left the bedroom, shutting the door behind her. She slowed her pace as she walked towards the kitchen, buying herself a couple seconds to text Peter about Ned's surprise visit. Since he hadn't told her about it at all, it was plausible that he had forgotten about it himself. She came to an abrupt stop when she saw the thin layer of smoke in the kitchen and May fanning the oven where a burnt turkey meatloaf sat.

"Any of it salvageable?"

May faced her Brynn, a soft smile pulling at the corners of her mouth. "I wouldn't risk it."

"So, we're going out for dinner?" She asked.

"That seems to be the consensus," her aunt said as she threw the towel in her hands on the counter. "Did Peter—"

The sound of a soft crash drew Brynn's attention over her shoulder. Her eyes widened when she realized it must have come from her bedroom. She faced May and started to back out of the kitchen.

"That was probably just Ned. I'll go see what's going on."

She didn't wait to hear her aunt's response. Instead, she turned around and practically sprinted to her bedroom door, pushing it open just enough to slip inside. Her jaw dropped when she saw her brother standing in the middle of the room, still donning his Spider-Man suit, and Ned just staring at him in awe.

"Brynn?" Her aunt's voice came through the door and made her jump into action.

"Your suit!" She whispered harshly at her brother as she grabbed one of his shirts off the dresser. Peter pressed the spider emblem in the middle of his chest and the suit fell to the floor. He kicked it aside as Brynn tossed him the shirt to change into. She took the spot beside him just as the door opened and May strolled into the room.

"You guys want to get Thai since that recipe was such a disaster?" She asked as she pulled the clip out of her hair. Her gaze slid over the three teenagers in the bedroom, landing on the third. "Ned, you want Thai?"

He smiled. "Yes—"

"No," Peter and Brynn chorused.

"He's got a thing," Peter added.

Luckily for the twins, Ned decided played along. "…a thing to do after."

Brynn pursed her lips as she exhaled quietly. She only hoped that her aunt would buy their confusing response. May hesitated in the doorway for a moment, but eventually nodded.

"Okay," she said. She grabbed the doorknob, pausing as her eyes shifted to Peter. "Maybe put on some clothes."

Brynn waited until her aunt shut the door behind her to turn to her brother. He pulled his shirt on over his head and met her gaze. "Why didn't you tell me Ned was here?!"

She rolled her eyes. "Your comms went out during the fight and I tried to called you to make sure you weren't dead. You were the one that didn't answer your phone!"

Peter's expression fell. "I was calling Happy. You could have texted me."

His sister opened her mouth to rebuff his remark, but she managed to refrain. She looked to their best friend instead, who still appeared to be in shock. "You okay, Ned?"

"My best friend is the Spider-Man…" he thought aloud. Trying to convince him otherwise would be a futile effort so Brynn confirmed his realization with a nod. "Who else knows about this?"

"No one!" Peter was smart enough to keep his voice at a low volume even though it was obvious he wasn't calm in the slightest.

Brynn quirked her head to the side. "Well, I know… and Tony Stark since—"

"—he made my suit," Peter finished Brynn's sentence before the words could form on her tongue.

Ned's eyes widened as his attention went to the suit on the floor. "Tony Stark made you that?"

He continued quickly, not giving Peter the chance to respond. "Does this mean you're an Avenger?"

Brynn snorted. "Hardly"

"Basically," Peter said at the same time. He shot Brynn a look, but she ignored it. She turned her gaze back to Ned who seemed to be struggling with the news.

"Ned, we need you to promise you won't tell May—or anyone for that matter." She stepped towards him as her expression sobered. "You have to keep this a secret."

Ned's faced scrunched. He was more confused by her request than the news that his best friend was Spider-Man. "What? Why?"

Peter came up beside Brynn. "May would shut this down the moment she found out. You know what she's like. Please, Ned!"

"I'm going to tell you the truth: I don't think I can keep this a secret," he admitted, his words tumbling over one another. "This is the greatest thing that's ever happened to me!"

Brynn closed the distance between herself and Ned. She squared her shoulders as she stared back at him. "May deserves a break, Ned. After everything that's happened to her, she deserves to just be happy and safe. If we bring this into her life, we run the risk of hurting her and we can't do that."

Peter's gaze lingered on his sister for a moment longer. They rarely talked about the most recent loss in their family, but it still affected them from time to time, especially May. He swallowed the lump in his throat and looked at their friend. "Please, Ned. Just swear you won't tell anyone."

"Okay," he said without hesitation. "I swear."

Brynn sat down on her brother's bed as he tried to get Ned out of their room. Peter agreed to answer all of the questions their friend had at school the next day, but Brynn had a feeling he'd come to regret that promise. Once they were alone, Peter exhaled, placing his hands over his face.

"I bet you're regretting not calling me back right about now," Brynn said, offering her brother a half-hearted smile when he dropped his arms to his sides. He shook his head as he leaned against the door.

"I can't believe this is happening."

"Did you really think we could keep this a secret forever?"

"No, but I thought we'd last longer than this," Peter answered.

"Maybe it's good we have someone to talk to about this," his sister said with a shrug. Her mouth opened and closed as she struggled to find a way to bring up her next idea. She cleared her throat. "And, maybe, we could think about telling Dylan about the, uh, spidey stuff."

Peter pushed himself off the door, his eyes narrowing. "What? No way. The more people that know about this, the bigger the chance that it will get out. We can't risk it, Brynn."

"But Dylan's way more likely to keep this a secret than Ned." She tilted her head to the side when her brother's clenched his jaw and dropped his gaze to the floor, his telltale sign that he was deep in thought. "Besides, he's our best friend, too, and it's a little unfair that he's the only one being left out of this."

Peter exhaled heavily as his sister watched him, waiting for his response. "I'll think about it, okay?"

Brynn nodded and stood from the bed. She grabbed her jacket off her bunk, letting out a quiet laugh. "Well, I'm just glad I'm not the one who has to explain what happened to your backpack… again."

"Oh, my God," Peter sighed. "I forgot about the backpack."

Brynn smirked as she pulled on her coat. "What does that make it now? Six?"

He dropped his head into his hands, groaning softly. "Five."

She patted his shoulder encouragingly as she walked past him towards the door. Brynn only hesitated to leave when she noticed Peter was still holding his head in his hands. The night's events had left her brother tired and worried, she knew.

"Hey," Brynn murmured as she approached him slowly. He lifted his head to meet her gaze and she gave him her best smile, hoping it would help lift his spirits. "Dinner will be over before you know it and we'll figure out this Ned thing together. Then you can go back to obsessing over Liz and pretending we're Avengers."

Peter laughed for the first time that night. He nodded at his sister as the corner of his lips curled upward. "Sounds like a plan."

Brynn offered him a fleeting smile before leaving him to change his clothes. She let out a shaky breath as she shut the door behind her, taking a moment to gather herself. Ned discovering their little secret worried her more than she'd let Peter believe. She tried to spin it to their benefit, but her brother was right. The more people who figured out who Peter really was, the harder it would become to keep their loved ones away from it. While his crime-fighting antics hadn't proved to be too life-threatening, Brynn had seen enough of what the Avengers had gone through to know that could change in an instant. She didn't have much else to lose except the people she loved, but no matter how much the thought of endangering them unsettled her, she'd put on a brave face for Peter. All their lives, the twins relied on each other more than anyone else and Brynn had promised herself that she wasn't going to be the one to let him down.


End file.
